Diana Freeburg came to Ann Arbor's Argo Canoe Livery Saturday afternoon with the intention of paddling the Huron River to Argo Park.

Freeburg, who was celebrating her birthday with family, had to settle for a "stillwater" paddle in Argo Pond because the city had shut down portions of the river after a downed power wire ended up in the water Saturday morning.

"We were kind of disappointed," Freeburg said as she kayaked near the livery launch with her father, son and niece around 3 p.m. Saturday.

Meanwhile, downriver near the Fuller Road bridge, DTE Energy crews were working to "de-energize" the 4800-volt distribution line that snaked into the middle of the river, said Jeff Lacombe, the field construction coordinator for DTE at the scene.

Lacombe said paddlers needed to be kept out of the area as a precaution. Ann Arbor city police had an officer stationed on the Fuller Road bridge to warn anyone floating down the river in that area. Park officials at the Argo Livery had not let anyone downstream since around 9 a.m., about an hour after a utility pole toppled in the woods between the bridge and a railroad trestle near the University of Michigan Hospital.

Witnesses at the hospital called authorities around 8 a.m. to report several loud explosions, fire officials said. DTE Energy spokeswoman Randi Berris said the cause wasn't immediately known, but it was eventually discovered that a dead ash tree fell onto the wires and brought down the whole utility pole.

"The damage was pretty extensive," Berris said.

About 600 DTE customers were initially without power. As of 4 p.m. all but "a handful" of customers had their power restored, Berris said.

The situation was taking longer to resolve than anticipated. Earlier Saturday, Berris said crews would be finished by afternoon, but that time was changed to 8:30 p.m.

Once the wire was "de-energized," crews planned on sending a worker out into the water with waders on to pull it out of the river. River traffic would be allowed once that happened, officials said.